package cn.jc.test.instanceofffff;

public class B extends A {

	public static void main(String[] args) {

		A a = new A();
		B b = new B();
		a = b;
		System.out.println(a instanceof B);
	}

	public static void getNumber(A a) {
		if (a instanceof B) {
			B b = (B) a;
		}
	}
}
